Paul Taylor on Nostr: The "Lemma" wasn't Zorn's. Even in his paper it was an Axiom. The proof of the Lemma ...

The "Lemma" wasn't Zorn's. Even in his paper it was an Axiom. The proof of the Lemma was by Kuratowski in 1922: see www.paultaylor.eu/trans/ which now finally has the whole of K's paper,